Railway cars are useful for transporting large amounts of cargo. Although in some applications it is desirable to manufacture large railway cars, the Association of American Railroads (AAR) has placed constraints on the size of railway cars for safety purposes. For example, cross-sectional widths and heights of railway cars are generally limited by applicable AAR clearance limitations, which specify a maximum width and a maximum height of a railway car at the center of the railway car and also specify maximum heights and widths at other locations along the length of the railway car. Because of applicable AAR clearance limitations, designers often increase the cargo carrying capacity of a railway car by increasing the length of the railway car. Unfortunately, as the length of a railway car increases, the width allowed by applicable AAR clearance limitations decrease to take into account the travel of the railway car around a curve. While traveling around a curve, a portion of a railway car may extend outside a clearance plane specified by AAR limitations, which is not acceptable. Therefore, stricter width clearance limitations are applied to longer railway cars to avoid a long railway car making contact with a structure adjacent the railroad.
Thus, AAR clearance limitations also generally limit the width-to-length ratio at which a railway car may be constructed and therefore further restrict cargo carrying capability of a railway car. The amount of cargo a railway car may carry directly impacts profitability of a railway carrier and is therefore important. Thus, maximizing the amount of cargo a railway car can carry while staying within AAR clearance limitations is desirable.